Shredding machine



y 1951 AYH. MENKIN ETAL 2,554,114

SHREDDING MACHINE Filed Aug. 6, 1948 5 Sheets-Sheet l 2 flc i. I 263 y1-951 A. H. MENKIN ETAL 2,554,114

SHREDDING MACHINE Filed Aug. 6, 194a 5 Sheets-Sheet 2 ATTORNEYS May 22,1951 Filed Aug. 6, 19.48

A. H. M ENK|N ET AL SHREDDING MACHINE 5 Sheets$heet 3 ATTORN EYS May 22,1951 A. H. MENKIN ET AL 2,554,114

SHREDDING MACHINE Filed Aug. e, 1948 '5 Sheets-Sheet 4 ATTORNEYS May 22,1951 A. H. MENKIN ET AL SHREDDING MACHINE 5 Sheets-Sheet 5 Filed Aug. 6,1948 Patented May 22, 1951 SHREDDING MACHINE Arthur H. Menkin,Elmhurst,-and Charles H. Morhardt, Baldwin, N. Y., assignors to TheShredmaster Corporation,

Delaware a corporation of Application August 6, 1948, Serial No. 42,774

Claims. (01. 164 -60) This invention relates to shredding machines moreparticularly of the type adapted to cut paper or other material intonarrow strips.

It is among the objects of the invention to provide a machine of theabove type that is neat in appearance, durable, relatively compact, easyto assemble and relatively noiseless in operation, that functions with aminimum of supervision requiring the operator only to feedmaterial'thereto and remove the collected shredded material, that it notlikely to clog or jam during the operation thereof but in the remoteevent of clogging or jamming may readily be cleared, that functions witha minimum of vibration, the speed of which may readily be changedWithout need for special tools, that is designed to pre vent injury tothe operator having but a minimum of exposed parts and that may readilybe disassembled for maintenance or service.

Another object of the invention is to provide a machine of the abovetype which may be used for slippery material such as waxed paper andensures positive movement of such material through the machine.

Another object is to provide a machine of the above type wherein thematerial to be cut may automatically be fed into the machine.

Another object is to provide a machine of the above type wherein lettersand other documents may readily be cut into small segments.

According to the invention these objects are accomplished by thearrangement and combination of elements hereinafter described andparticularly recited in the claims.

In the following drawings in which is shown one or more of variouspossible embodiments of the several features of the invention,

Fig. l is a perspective view of the machine,

Fig. 2 is a transverse sectional view taken along the line 2--2 of Fig.1, I a

Fig. 3 is a front elevation of parts broken away,

Fig. 4 is a transverse sectional view on a larger scale taken along line44 of Fig. 3, i

Fig. 5 is a longitudinal sectional view taken along line 5--5 of Fig. 4,

Fig. 6 is a fragmentary plan view on a smaller scale taken along line 66of Fig. 5,

Fig. '7 is a sectional view on a larger scale taken along line l'! ofFig. 6,

Fig. 8 is an exploded perspective view showing the cutting blades, thestrippers or combers and the spacing members,

Fig. 9 is asectional view on a larger scale taken along line 9-3 of Fig.2,

the machine with Fig. 10 is a fragmentary view of another embodiment ofthe invention,

Fig. 11 is a fragmentary perspective view of still another embodiment ofthe invention,

Fig. 12 is a plan view of another embodiment of the cutting blade, and

Fig. 13 is a view similar to Fig. 12 of still another embodiment of thecutting blade.

Referring now to the drawings, the machine comprises a substantiallyU-shaped frame 2| preferably of cast iron, the legs 22 thereof eachhaving a transverse flange 23 at the lower end thereof extendinglaterally outward therefrom, said flanges 23 mounting casters 23 wherebythe machine may readily be moved. In order to prevent the legs 22 fromspreading, angle irons 25 and 23 are provided extending longitudinallyof the frame and affixed at each end respectively by screws 24, totransverse flanges 30 extending laterally inward from the lower ends oflegs 22 and preferably integral therewith.

The cross piece of the frame which forms a table portion 2'! near themid portion thereof, has a depending skirt 28 on the front edge thereof,preferably formed integrally therewith and which extends the entirelength of the cross piece. The rear edge of table portion 21 has adepending portion preferably integral therewith forming a chute 29 whichis substantially the same width as table portion 2! and slopesrearwardly as shown in Fig. 2.

Each end of the cross piece adjacent table portion 21 forms a bed orbase 3| and 32 respectively, substantially the width of the legs 22,base 3| being at a lower level than table portion 21 and base 32, asshown in Fig. 5. Base 3| has a longitudinal slot 33 (Figs. 3, 4) there-'through, adjacent skirt 28 for the drive transmission to be hereinafterdescribed.

Mounted on bed 3! and extending upwardly therefrom is a gear box 34rigidly aflixed to bed 3| by screws 35 extending through flange 43 atthe lower edge of the gear box 34 and preferably integral therewith. Thegear box 34 has a removable cover plate 33 afiixed on the top thereof byscrews 37, a threaded plug 38 being provided in said cover plate 36 toclose the lubricant inlet. Drain plugs 33 are provided in the bottom ofthe gear box 33, the bed 3i having an aperture 4! therein to permitready access to said plugs 39 to drain the oil from the gear box 34.Desirably a test plug I36 is provided threaded in an opening in sidewall I l l of the gear box at a height above the bottom of the gear boxbelow which the level of the lubricant therein 2 U should not fall. Thusif with the test plug I removed. no lubricant'flows from the opening,the gear box should be rechanged with lubricant.

The front and rear walls 43 and 44 respectively of the gear box 34, nearthe bottom thereof, have transversely aligned recesses 45 and 46therein, with apertures 4! and 48 respectively therethrough. Extendingthrough said apertures is a worm shaft journalled in ball bearings 52and 53 near its front and rear ends respectively. Bearings 52 and 53 areseated in recesses 45 and t5 against the inturned rims 55 and 56 thereofrespectively. In order to prevent axial movement of shaft 5| in itsbearings and retain the hearings in their respective recesses, the

shaft 5| is threaded as at 51 and 58 and nuts 59 and BI are afiixedrespectively on said threaded portions.

To prevent entry of dirt and dust into the bearings 52 and 53 andprevent leakage of oil from the gear box 3 8, a cover plate 54 isaffixed to the rear wall 44 of the gear box over bearing 55 by screws 65and a similar cover plate 6? is a'ffixed to the front wall 43 of thegear box 3 5 over bearing '52 by screws 68, the last named cover platehaving an oil seal or packing I2 around opening '69 to prevent leakageof oil through aperture 59 through which the front end H of the wormshaft 5| protrudes.

Affi-xed to the front end II of worm shaft 5| over slot 33 in base 3!are a plurality of pulleys of different diameters two beingillustratively shown designated by the numerals I l and T5. In order torotate the pulleys I4 and I5 and drive worm shaft-5|, a motor M isprovided positioned beneath the gear box 34 and a ffixed by bolts TI tosubstantially rectangular base or platform Ti Platform 18 has a pair ofaligned depending cars '59 on each side thereof through which atransverse pivot rod 8| extends, rigidly afiixed at each end in angleirons and 26 pivotally to mount platform- 13. In order to limit thepivotal movement of platform 18, a transverse rod 82 is provided 25 nearthe free end of platform I8. bolt 5d is pivoted on rod I12 and has itsthreaded end 83 extending through an opening in platform '58, a pair ofnuts 85 being provided screwed on the threaded end of eye bolt 85against each face of platform I8 rigidly to clamp the lattertherebetween.

The drive shaft 86 of motor M has a plurality of pulleys P thereon,illustratively two in number of different diameter, the smaller pulleyon shaft 35 being aligned with the larger pulley I4 on shaft 5| and thelarger pulley on shaft 86 being aligned with the smaller pulley I5 onshaft 5|. It is thus apparent that by placing the belt S'I on differentpairs of aligned pulleys, either of two speeds may be selected. It is ofcourse to be understood that a greater number of pulleys could beprovided on shafts 86 and 5| to provide for a greater range of speeds.In order that a single size belt can be used for different speeds, thealigned pairs of pulleys are of such diameter that the length of thebelt around each of the aligned pairs of pulleys will be the same.

Positioned on base 32 and extending transversely thereacross as shown inFigs. 5, 6 and 7 is a substantially L-shaped tail-stock 9|. The base 92of the tail-stock has a pair of longitudinally aligned slots 93 and 94therethrough on each side thereof through each of which extends a screw95 threaded into an associated Opening 96 in base 32, the slotspermitting longirigidly mounted in angle irons 25 and 7 An eye' 4tudinal adjustment of the tail-stock when the screws 95 are loosened. Inorder to facilitate such adjustment, a pair of handles 91 are providedpreferably integral therewith on opposite sides thereof.

Extending laterally outward from, the upright portion 98 of thetail-stock 9| are a pair of hubs 55 and |5I the latter being positionedbelow the former and forwardly thereof as shown in Fig. =6. The hubs 99and IOI have openings I63 and I54 therethrough respectively, alignedwith corresponding openings I05, I96 and I61, I98 in the side walls I09and III respectively of the gear box 34.

A pair of shafts I I2 and H3 are provided positioned longitudinally ofthe frame 2| and extending through openings I03, I85 and Iii? and I58,I66 and I 08 respectively. As the construction and mounting of saidshafts H2 and H3 are substantially identical only the former, i. e.shaft H2 will be described in detail, corresponding parts of the latterhaving the same reference numerals primed.

Shaft H2 has a reduced portion .I I5 adjacent side wall I09 of the gearbox 3 around which a ball bearing H5 is positioned, the latter beingseated against the inturned flange III of opening I05.

Shaft II2 has an encompassing collar H9 adjacent bearing H5 with a notchtherein whereby the collar may be keyed to shaft I I2 in the mannerhereinafter described so that collar H9 will rotate with shaft H2.

A seal ring I-2I is provided encompassing shaft H2 and collar H9 andseated in a recess I22 in side wall IE9, said seal ring being retainedin said recess by screws I23. As shown in Fig; 5 the inner face I24 ofcollar H9 extends slightly beyond the face of seal ring I'2I The sealring has an annular washer I25 preferably of felt, on the inner edgethereof, which abuts against collar H9 to prevent leakage of oil fromthe gear box and reduce the friction between the collar and seal ring.

The end of shaft H2 is journalled in a ball bearing I25, the latterencompassing the reduced portion I2"! of the shaft and seated againstshoulder I 218 form-ed by said reduced portion. The bearing I25 which ispositioned in opening I61 in side wall III of the gear box 34 isretained on shaft I I2 bymeans of a nut I29 threaded on the end I3I ofthe shaft H2.

Keyed on the portion of shafts H2 and H3 in the :gear box are meshedspur gears I32 and I33 respectively which are spacedfrom bearing H6 andH5 by means of sleeves I34 and I34 respectively.

By means-of anut I35 screwed on the threaded portion I36 of shaft H2,spur gear I 32, sleeve I 3 3, bearing H5 and collar H9 are retainedagainst axial displacement on shaft H2.

A-lso keyed in shaft H3 is a worm gear I37 spaced by sleeve 1:88 fromspur gear I33 and by sleeve -I4 I from hearing I26 positioned in openingI08 in side Wall III of the gear box. A nut I29 screwed on the threadedend I-3I" of shaft H3 prevents axial displacement of bearing I26, sleeveI41, worm gear I37, sleeve I33, spur gear I33, sleeve I34, bearing 1H6and collar H9.

The worm gear I'B'I meshes with a worm I64 keyed on worm shaft 5I todrive shafts H2 and H3 when the worm shaftis-rotated in the mannerhereinafter described.

In order to prevent the entry of dirt and dust into the gear box andalso to prevent the leakage of oil therefrom, cover plates I41 and I4?are provided affixed to the gear box over the ends I3I and I3I' of shaftH2 and H3 respectively by screws I48.

Mounted on shafts H2 and H3. between end wall I09 of the gear box andupright portion 9.8 of the tail stock are a series of opposed circularcutting knives IBI and I52 respectivelywhich aresecured to theirrespective actuating shaft in any desired manner, keys I53 and I54 beingpreferably used, positioned in the keyways I55 and I56 respectively inthe shafts and engaging corresponding notches I5'I in the knives as wellas corresponding notches in the associated collar H9, H9. A series ofspacer collars-I58; and I 59 each having a notch IBI is similarlymounted on each shaft between consecutive cutters, and each series ofknives is so located with reference to the other as to be positionedopposite to the spacer collars of the opposing series with the cuttingedges thereof overlapping.

The cutting knife cleaning devices or combers I52 and I63 in thismechanism which are mounted in like plurality between the knives I5I andN2 of each series, each takes the form of a substantially circular platehaving an opening I68 therethrough of greater diameter than that of theassociated spacer I58 or I59 and preferably encompassing said spacersrespectively. As the thickness of the spacers is slightly greater thanthat of the cornbers, the latter will ride between the faces of thecutting knives with but a minimum of friction.

Suitably formed extension ltd and I I35 are provided on the combers IGZand I63 respectively, preferably integral therewith and lying in thesame plane therewith, each of said extensions having a substantiallyrectangular opening It? therein through which the supporting bars useand I69 respectively extend.

Bar M58 is affixed at one end by means of a screw I'II to the top of thegear box 34 and extends longitudinally of the shaft II2 to thetail-stock SL The other end of bar I63 has a longitudinal slot I12therein through which a screw I'IS extends threaded into an opening I14in the top of the upright wall 98 of the tail-stock. Thus bar I68supports members ltl with the extensions I66 thereof in a substantiallyupright position.

Bar I69 is affixed at one end by screw 75 to the front wall of the gearbox and extends longitudinally of the shaft II 3 to the tail stock SI.The other end of bar 169 also has a longitudinal slot I16 thereinthrough which a screw IIIextends threaded into an opening in hub IilI ofthe tail stock as shown in Fig. 6. Thus bar I59 supports members I63with the extensions I65 thereof at substantially right angles toextensions I 64. As shown in Fig. 2 the combers are so formed that atthe points indicated by the numerals I78 and N9 the opposed and adjacentedge portions thereof lie within the peripheral edges of the knivesbetween which they are positioned. From this point the edge portions arecarried gradu ally outward to the points I8I and I32 where they overlapthe peripheral edges of the knives.

Thus as the material is fed to the machine and cut, the strips whichadhere betweenthe cutting edges of the knives are carried thereby fromthe point indicated by the numeral I83 to the point where they encounterthe overlapping edge portions I8I and I82 of the combers. I62

6 and I63 respectively and areforced out from between the cutting edgesof the knives.

-The positioning of the knife, spacer and comber elements may readily beseen in Figs. 5 and 8, the elements shown in Fig. 5 being exaggerated inthickness to facilitate a clear understanding of the machine.

In a preferred embodiment of the invention the machine is set up withelements inch in width. If it is desired to shred up to inch, knives,combers and spacers are set up on the shaft singly as shown. If it isdesired to shred Te inch strips, the individual elements are placed onthe shaft two at a time. If inch widths are desired, the elements areplaced on the shafts three at a time and so on. This change of width mayreadily be accomplished by the user as desired.

Encompassing the reduced portions I9I, I9I of shafts H2 and H3respectively and seated against shoulders I92 formed by said reducedportions are ball bearings I93, I83 respectively of diametersubstantially the same as the opening I83, H54 in hubs 99 and IBIrespectively so as to permit axial movement of the shafts H2 and H3 andtheir respective bearings I 93 and I93 in the manner hereinafterdescribed but preventing lateral movement thereof. Bearings I 93 and I93are retained against their associated shoulders I92 by sleeves I94encompassing the end portion N5 of the respective shafts and retainedtherein each by a nut I96.

Shafts H2 and H3 each has an encompassing collar I9! with a notch I98therein through which keys I53 and I54 respectively extends therebyaffixing the collars to their respective shafts to rotate therewith, yetpermitting the collars to be moved axially thereon. Abutting againsteach of the collars I9! respectively is a nut I99 screwed on thethreaded portion Zill of the shaft adjacent collars I97 and by means ofwhich the axial position of the collars may be determined.

Seal rings 202 and 202 are also provided, encompassing shafts H2 and H3and their associated collars I91 respectively and seated in recesses 283and 203' respectively in the inner face of upright portion 98, andretained in said recesses by screws 204. Each of the seal rings has anannular washer 285 preferably of felt on the inner edge thereof whichengages collar I91 to reduce the friction between the seal ring andcollar.

To prevent injury to the operator and also to prevent the entry of dirtand dust as well as the shredded material into the machine, which mightcause jamming of the latter, suitable coverings are provided.

As shown in Figs. 1, and 3, the skirt 2% and legs 22 of the frame have aflange 2H to which a sheet metal cover 2I2 is affixed by screws 2I3. Inorder to provide access to the motor M and pulleys thereon, a door 2% ishingedly mounted on the sheet metal cover 2 I2 as at 2 I5. A sheet metalhousing 2I6 is provided for the gear box 34, which is affixed to bed SIand is provided with a door 2!! hinged to the front wall 2I8 of thehousing -2I6 as at 2I9 to provide access to pulleys I I and I5. A sheetmetal housing 22I is also provided for the tail-stock 9i and is affixedto bed 32 as shown in Fig. 5.

Extending longitudinally of the machine over the portion of shafts H2and II 3 on which the knives are mounted is a sheet metal reflector 222afiixed at each end to housing 2I6 and 22I respectively and providedwith illuminating means such as bulbs 225 to cast light on the cuttingportion of the machine.

To facilitate feeding material into the machine, a table 226 isprovided. As shown inF'igs. 2 and 3 the table has a substantially-L-shaped bracket 22'! afiixed therebeneath along each side edge thereof.As shown in Fig. 2 the vertical leg 228 of the bracket has an elongatedslot 229 therein and a finger 23I extending longitudinally thereofhaving a notch 232 therein. A pair of spaced studs 233 and 234 areprovided on each of the opposing walls I09 and 98 of the gear box andtail-stock respectively, extending laterally outward therefrom. Studs233- extending through the longitudinal slot 229 of the associatedbrackets 22! pivotally to mount the table, the latter being retained ina horizontal position by seating studs 234 in notches 232 of fingers 23fas shown in full lines in Fig. 2.

The table 226 has an inclined lip 24? rigidly afiixed to its rear edge243 to facilitate feeding the machine when the table is in horizontalposition.

In order to safeguard the operator as he feeds the machine, a pivotedshield 249 is provided comprising a horizontal portion 25! substantiallythe width of the table 226, having an upturned frontedge 252 to which aknob 253 is afiixed and a. downwardly inclined rear portion 254substantially parallel to inclined lip 24! of table 226 as shown in Fig.2.

Rigid with portion 25I and extending obliquely upward therefrom is aplate 255 having a window 256' therein preferably of plastic or othertransparent shatterproof material. The upper edge of plate 255 has arearwardly extending flange 251' preferably integral therewith, at eachend of' which is afiixed a stud 258 extending longitudinally of theplate 255.

A pair of L-shaped brackets 259 are affixed respectively on the top ofthe housings 256 and 22I, the upstanding leg of said brackets eachhaving a notch 2H therein in which studs 258 may respectively bepositioned pivotally to support the shield 249. In order to limit thepivotal movement of shield 229 a bracket 263 isaffixed at eachedge-of'horizontal portion 251, the laterally extending arms 264 of thebracket resting on the top of housings 216' and 22I respectively whenthe shield is in closed position. Associated with one of said brackets263 is an electrical switch 266 mounted in housing 2l6. The lateralextending arm 264 of bracket 263 contracts the operating plunger 26'! ofthe switch when the shield is in closed position to closethe switch, thelatter automatically opening when arm 264 is moved away from plunger 26?by the pivoting of shield 249.

An upright shield plate 2" is also provided affixed beneath table 226 tobed portion 21 as shown in Figs. 1 and 2 to prevent the operator fromtouching the cutting knives when the machine is in operation and also toprevent backing up of the shredded material when the machine isfunctioning.

Afiixed on the table 226- on each side thereof near the free end of thetable, is an adjustable paper guide, preferably comprising two L-shapedmembers 236 and 23?, the vertical legs 238'and 239 of which are clampedtogether by a wing'nut and; bolt". 2, the latter extending through avertical slot 242 in leg 239 to permit vertical adjustment of thelaterally extending'leg 2-43" of the guide. Thefoot 244 of the guide issecured to. the: table 226. by wing nut and bolt 245 the latterextendingthrough a slot 246 in said foot to permit'lateral' adjustment of theguide on the table.

In order to energize motor M, a switch box 212 isprovided, mounted on abracket 213 atfixed to skirt. 28 of the frame. The switch box isconnected by a lead 215 to control box 216 mounted on leg 22 of theframe as shown in Fig. 2.

The switch box preferably has three buttons, i. e. start, stop andreverse, the latter button requiring constant pressure thereon foractuation thereof. As the circuit and control elements for the switchbox which are. contained in the control box: are conventional, they willnot be further described.

Adjustment and operation Withthe. machine assembled as heretofore.described, nuts I35 and I99 on shaft H2 and nuts I29 and I99 on shaft H3are tightened to compress the knives'and spacers therebetween so thatthey are rigidly retained on. their respective shafts. As combers I52and I63 are positioned between the knives, encompassing their associatedspacers which are thicker than the combers, the combers will ridebetween the knives with but a minimum of friction. As comberl62 on shaftH2 and knives I52 on shaft II3, on the left side of the machine as.seenin Fig. 5, adjacent the seal rings I2l, and I2! respectively of gearbox 34 are spaced therefrom by reason of the slight protrusion ofcollars H9 and 9' beyond the inner face of the. seal rings, therewill beno contact between the knife: and comber and their respective seal ringsand hence no frictiontherebetween. This space is so small that there islittle likelihood of the shredded ma.- terial jamming therein whichwould interfere with, the operation of the machine.

As the tail-stock 9| is movable longitudinally of the frame, accuratetolerances in the construction of the machine is not required to ensurethat the space between seal rings 202 and 202., and the comber and knifeadjacent thereto tating in a clockwise direction and shaft I-I3 rotatingin a counterclockwise direction; As-the window 256 in the shield 249affords a clear view of the illuminated knives, the operator may readilyfeed material thereto by placing the same on table 226 and moving itbeneath shield 249 through the slot formed by inclined portion254thereof and lip 241, so that it is caught by the rotating knives whichwill pull the material therebetween and cut the same into strips, thelatter thereupon dropping down on chute 29 to slide out of the machine.To prevent accumulation of the strips beneath the machine whencasters'are'used, a pivoted plate 289 is desirably provided which isaligned. with chute 2.9 to direct the strips-away from the machine. Thisis clearly shown in Fig. 2'.

If paper is to be shredded that is of greater widththan the cuttingportion of the machine. the adjustable paper guides will cause the paper9 to be curled over as it is fed into the machine thereby preventingsuch paper from getting caught in the spaces adjacent the seal rings andpossibly jamming the machine.

If the machine should jam, it is merely necessary for the operator topress the stop button, then momentarily press the reverse button whichwill reject the material between the blades. The material may then beproperly positioned in the machine and the start button again pressed.

In the eventuality that the reverse rotation should fail to clear themachine and the operator should desire manually to pull the materialjammed between the knives, in order to reach the knives, he must firstlift the shield 249. This will remove bracket arm 234 from safety switchplunger arm 23'! and stop the machine thereby preventing any possibilityof injury.

If the operator should desire to change the speed of the machine, heneed merely press the stop button, open doors 2M and 2|! and switch thebelt 8! to the desired size pulleys. To facilitate such adjustment, thenuts 85 on eye bolt 34 are first loosened and the platform pivotedupwardly to slacken the belt 31. With the belt on the proper pulleys,the weight of the motor on the platform will keep the belt taut and thenuts 85 may then be tightened to retain the platform in place.

With the construction herein described when material is inserted betweenthe knives, any tendency of the shafts H2 and H3 to bow materially isprevented by reason of the double bearing support therefor in the gearbox 34. If not for such dual support, the bowing might move the ends it!and i3! of the shafts out of line resulting in severe vibrationwhich'would cause considerable noise and tend to loosen the operatingparts of the machine resulting in breakdown of the latter, thusrequiring-constant maintenance thereof.

When it is desired to out slippery material such as waxed paper whichmight not readily be caught by the smooth periphery of circular knivesand pulled therethrough, the cutting knife 282 as shown in Fig. 12 orthe knives 233 shown in Fig. 13 could be used. Knife 282 has a smallnotch 284 in the periphery thereof which would catch on the paper andpull it through and the flats 285 on knives 283 would also serve thesame purpose.

In Fig. an embodiment of the machine is shown which is especiallydesigned to cut confidential documents such as letters or other papersinto small pieces. As shown in the drawing two parallel shafts 281 and288 are provided lying in the same horizontal planes with a plurality ofknives 289, spacers 290 and combers 29! on each shaft. As theconstruction and assembly of such machine is substantially similar tothe one shown in Figs. 1 to 9, it will not be described in detail.

It is to be noted that substantially the entire periphery of the combers29l lie within the periphery of the knives 283 and only near the top ofthe knives as at 292 does the sloping edge 293 of the combers extendbeyond the periphery thereof.

A hopper 294 is provided with the outlet 235 thereof positioned directlyover the overlapping portion 336 the knives and deflectors 296 areprovided at the outlet 295 extending laterally outward and downwardly soas to extend beyond the knives.

When the paper is dropped into the hopper it will fall between theknives and initially be shredded into strips. The strips will stick inthe space between the knives and be carried around until they abutagainst the sloping edge 293 of the combers 29! to be forced out of thespace between the knives. As the strips are forced outwardly, they willabut against the deflector 296 as at 291 and curl over the top of thecombers as at 298 to again pass between the cutting edges of the knives.As the strips will now not be aligned with the spaces between the knivesbut will be at an angle thereto, they will again be cut, but this timeinto smaller segments, the smaller of which will not stick between theknives but will fall downwardly. The larger segments which remainbetween the knives will again be forced outwardly by the combers and bedeflected over the top thereof to again fall between the kniveswhereupon they will again be cut into still smaller segments. Thisprocedure will be repeated until all the paper has been cut into verysmall segments which will be discharged from the ma chine, whichsegments would be almost impossible to piece together and read.

The small segments may be collected in a basket (not shown) positionedbelow the overlapping edges 30!] of the knives to be subsequentlyburned.

In Fig. 11, the machine shown in Figs. 1 to 9 has been slightly modifiedso that a conveyer system may readily be incorporated therewith.

To this end a plurality of cutting knives 335, combers 332 and spacers303 are positioned on shafts 304 and 365 in the manner heretoforedescribed, illustratively in sets of four instead of the individualelements shown in Figs. 1 to 9. Alternate sets of combers 332 on thelower shaft 365 are replaced by pulleys 323 which latter are keyed toshaft 305 by key 301. It is of course to be understood that all of thesets of combers 362 on the shaft 385 could be replaced by pulleys 306 orsome intermediate arrangement could be used.

The pulleys 306 each have a continuous belt 333 therearound whichencircles an idler pulley 303 mounted on a shaft 3| l, the belt beingnorma ly retained in taut condition in a horizontal position.

To operate the machine shown in Fig. 11, the operator need merely placethe material to be shredded on the belts 3558 which will carry suchmaterial to the overlapping portion of the cutting knives, whereupon itwill be drawn therethrough. As the strips of material between thecutting knives encounters the combers 332 on shafts 384 and 335, thecombers will force the strips outwardly from between the knives so thatit may be discharged from the machine. In the case of the strips in thespaces between the knives occupied by the pulleys, the strips will abutagainst the belts and be forced outwardly from between the knives in thesame manner as if the combers had been used.

Thus by the above construction, the shredding machine may readily besupplied with a conveyor belt with resultant convenience in feeding themachine and increase in the output therefrom and this advantage may besecured without any material modification in the design of the machine.

As many changes could be made in the above construction, and manyapparently widely different embodiments of this invention could be madewithout departing from the scope of the claims, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illusl rative and not in a limitingsense.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent of the United States is:

1. A shredding machine comprising a pair of parallel rotary shafts, aseries of spaced circular cutting knives assembled on each of saidshafts and rigidly afiixed thereon to rotate therewith the cuttingknives on one of said shafts alternating with and overlapping thecutting knives on the other of said shafts, a series of stationarycombers on each of said shafts between the cutting knives thereonrespectively and spaced therefrom, each of said combers comprising asubstantially circular plate having a central opening therethrough forthe respective shaft, substantially the entire periphery of each ofvsaid plates lying within the periphery of said cutting knives, saidplates each having an extension lying in the same plane thereof andintegral therewith, said extensions protruding beyond the periphery ofsaid cutting blades at the top thereof, means engaging said extensionsto retain said combers in fixed position, a deflector plate positionedover each series of combers and means to feed material into said cuttingknives at the overlapping portion thereof.

2. The combination set forth in claim 1 in which the axes of saidarallel rotary shafts both lie in the same horizontal plane.

3. A shredding machine comprising a pair of parallel rotary shafts bothlying in the same horizontal plane, a series of spaced circular cuttingknives assembled on each of said shafts and rigidly afiixed thereon torotate therewith, the cutting knives on one of said shafts alternatingwith and overlapping the cutting knives on the other of said shafts,spacers between said cutting knives having contact therewith, a seriesof stationary combers on each of said shafts between the cutting knivesthereon respectively and spaced therefrom, each of said comberscomprising a substantially circular plate having a central openingtherethrough of greater diameter than that of the spacer andencompassing the latter, substantially the entire periphery of each ofsaid plates lying within the periphery of said cutting knives, saidplates each having an extension lying in the plane thereof and integraltherewith, said extensions protruding beyond the periphery of thecutting blades at the top thereof, means engaging said extensions toretain said combs in fixed position, a feed hopper having an inletpositioned over the overlapping portion of said cutting knives and aninclined deflector plate positioned over each series of combers andextending longitudinally of said shafts.

4. A shredding machine comprising a pair of parallel rotary shafts, aseries of circular cutting knives assembled on said shafts inalternating and overlapping relationship, spacers between said cuttingknives having contact therewith, a series of stationary combers disposedbetween the cutting knives of one of said shafts, means disposed betweenthe cutting knives of the other of said shafts to expel material frombetween said cutting knives, said means comprising a plurality ofpulleys rigid with said shaft and rotating therewith, said pulleys beingpositioned between the cutting knives on said shaft, a belt driven byeach of said pulleys, means to retain said belts in horizontal positionwhereby material may be placed on said belts to be fed to said cuttingknives and means on said shafts for holding the cutting knives andspacers together.

5. The combination set forth in claim 4 in which bearing means areprovided for each of said shafts on each side of the series of cuttingknives and spacers thereon and additional bearing means are provided foreach of said shafts at one end thereof.

ARTHUR H. MEN'KIN. CHARLES H. MORHARDT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 478,023 Rohan June 28, 18921,178,386 Edwards Apr. 4, 1916 1,319,496 Stachowski Oct. 21, 19191,725,176 Bevis Aug. 20, 1929 1,747,264 Rearick Feb. 18, 1930 2,086,476Quick et a1 July 6, 1937 2,160,999 Yoder June 6, 1939 2,202,843 EdwardsJune 4, 1940 2,210,018 Yoder Aug. 6, 1940 2,364,334 Wold Dec. 5, 1944FOREIGN PATENTS Number Country Date 155,138 Germany Oct. 24, 1904281,170 Great Britain Dec. 1, 1927 511,762 Germany Nov. 6, 1930 625,464Germany Feb. 10, 1936

